\begin{tikzpicture}
	\tkzDefPoints{0/0/A, 0/1/a, 1/0.3/b, 1.2/-0.5/c, 0.8/0.8/d}
	\tkzDrawLines[add=1 and 0](A,a  A,b  A,c  A,d)
	\tkzLabelLine[pos=1,above](A,a){$a$}
	\tkzLabelLine[pos=1,right](A,b){$b$}
	\tkzLabelLine[pos=1,right](A,c){$c$}
	\tkzDrawPoint(A)
	\tkzLabelPoints[below right, yshift=-0.3em](A)
\end{tikzpicture}

